Climate Change Past and Present
As our climate changes and the oceans warm, become increasingly acidic, and loose oxygen, it is increasingly important to understand how the changes we observe today compare to those in the Earth’s past. A primary goal of my research is to connect the past, present, and future of climate change using the microfossil record. Ongoing projects focus on (1) how East Pacific Oxygen Minimum Zones responded to rapid climate change through the last deglaciation, and (2) the spatial distribution of Oxygen Minimum Zones during the Pliocene, a period of stable warm climate.
Foraminiferal Abundances and Geochemistry
One of the best sources of information about past climates is the marine fossil record. In particular, the shells of foraminifera, single-celled marine organisms, represent one of the most widely used proxies for past environments, while simultaneously contributing to global carbon cycling. Understanding how these creatures respond to their environment is essential for a robust interpretation of their fossil record. I’ve studied changes in the geochemistry, morphology, and calcification of foraminifera in response to environmental variables (e.g. oxygen, temperature, and carbonate chemistry) on time scales of decades to millennia. Ongoing projects in this area are focused on (1) understanding the foraminiferal assemblages associated with low-oxygen and low-pH mid-water environments, and (2) linking the trace element composition of their shells with environmental parameters.
Laboratory Culture of Foraminifera
Laboratory culture of foraminifera has served as an important link for testing hypotheses about how their fossil shells reflect their growth environment. I have been extensively involved in laboratory culture of planktic foraminifera at several fied sites. Through this work, I seek to expand current understandings of the relationships between the geochemistry of foraminiferal shells, temperature, and pH. Laboratory culture of foraminifera has also resulted in important insights into the life history, biology, and physiology of important foraminiferal groups. My active research projects on this topic revolve around linking shell-bound trace elements to seawater concentrations in deep-dwelling planktic foraminifera.